The paper rebuilds the property right characters of state capital,and uses the series data of factor production and profit rate to test the origin of the low efficiency of state-owned enterprise,and judge which is more important, competition or the property right? It points out that,the state-owned property right structure has the passive relation- ship with the profit rate,but the competition is positive,and the low efficiency of state-owned enterprise is the com- pound result of both.So,only by strengthening the reform of property right and competition,the efficiency of state - owned enterprise will be promoted.